Final answer:
The Beatles were influenced by '50s rock 'n' roll through its rhythmic energy, guitar-based structure, and rebellious cultural spirit, which they incorporated into their own innovative music style.
Step-by-step explanation:
The '50s style of music profoundly influenced the Beatles by laying the foundation for the rock 'n' roll genre, which they would further develop and popularize in their own music. In the 1950s, rock 'n' roll was a fusion of African American rhythm and blues with electronic amplification and a strong backbeat. This integration of Black musical traditions into mainstream culture by artists like Elvis Presley and Chuck Berry broke racial barriers and introduced a rebellious spirit associated with youth and nonconformity. The Beatles absorbed these elements and were part of a larger movement that used music to challenge societal norms.
Rock 'n' roll of the '50s provided the Beatles with musical structures, such as the use of guitar riffs and energetic rhythms. It also offered a model of how music could encapsulate youthful defiance. As the Beatles' career progressed, they would take the essence of '50s rock 'n' roll and expand it artistically, allowing them to embody the suburban youth culture's rebellion against the monotony of the adult world.